1. Field of the Invention
In the world of traffic and transport an ever increasing number of electronic devices are being put into use; in particular there is a marked increase of computer applications, also on-board of vehicles. It is obvious that on-board computers should be perfected so that they can also be used for determining:
routes and distances;
generation of site information;
the use of these data for the purpose of navigation;
the processing of (coded) up-to-date route information via a radio receiver. The procedure to describe here concentrates on the technique of the initial collection of the data necessary for navigation.
To make navigation via the on-board computer possible, two conditions are to be met in principle:
(a) the availability of an electronic map, as it were the framework within or across which one moves, and
(b) the updating of the location of the vehicle within the limits referred to in (a).
The procedure to be described constitutes a means to solve the problem of the production and updating of data files for an electronic map as mentioned in (a) in the most efficient way.
The required data files which will be made for the purpose of navigation of the motorized road traffic now consist of two groups of data:
(1) metrical data: the system of co-ordinates;
(2) non-metrical data which are added to the metrical data. There are a great many non-metrical data, for the greater part referring to matters of traffic technique and other traffic and object information. These very large files can be made accessible to the user via CD-ROM only. Solving the problem of compiling and updating those files in a very efficient way depends, on the one hand, on the application of a perfectly equipped production process and, on the other hand, on a ready support of that production process by supplying it with up-to-date information, both to enable the file (=map) to be as complete and up-to-date as possible, and to largely reduce expensive additional investigation in the field. The procedure to be described is aimed at the last mentioned aspects.
This invention relates to a road inventory system for gathering visual data from which road data files can be generated, in order to compile and to update a road data base. This road inventory system consists of three main parts:
a mobile unit, for video registration and measuring;
a stationary unit for editing and post processing;
a customer set, a desk-top user display and retrieval system.
2. Description of the Prior art
U.S. Pat. No. 4,396,942 discloses a method for video surveying, comprising the steps of: video recording all locations to be surveyed from a predetermined control position, for subsequent playback on a monitor screen. The method uses an overlay to the monitor screen or actual measurement in the terrain to ascertain actual distances, and allow for adding notes to the video recordings. The video survey may be conducted from a moving vehicle, using a video cassette recording apparatus.
U.S. Pat. No. 4,635,136 discloses a method and apparatus for storing a massive inventory of labeled images. The inventory is produced on different frames of a video disc, from which the images may be randomly accessed for use in tax assessment, real estate sales and the like. Digital information is accessed from memory associated with a computer and monitored to define a route for a field rig, equipped with a video camera, which scans the images and provides TV signals in the order in which the digital information corresponding to the image to produce TV signals with labeling information therein. Pluralities of frames of the TV signals are recorded on a video recorder. A single frame is selected from each plurality and recorded on a different frame of the video disc record.
U.S. Pat. No. 4,495,500 discloses a system for gathering topographic data for use in computer generation of topographic maps of various forms. This system includes equipment mounted in an aircraft which can be flown over a terrain area which is to be surveyed. The equipment comprises a low frequency radar which is capable of penetrating foliage in the survey area for generating a signal representative of the distance from the aircraft to the terrain surface. Also a precision altimeter, temperature and humidity sensors, a clock and a digital recorder are included. The recording medium can be removed from the aircraft. Concurrent with the gathering of data in the aircraft, temperature and humidity data and at surface of the earth are gathered and recorded. Combination of the recordings can be used as computer input to produce accurate topographic maps.
U.S. Pat. No. 4,360,876 discloses an indicator system which satisfies multiple flight-mission requirements by providing an aircraft pilot with a visual display consisting of a movable map and navigational data. The map is stored in video form in a high-capacity compact mass memory consisting of a video disk. The system further comprises a symbol and character generator, intermediate memory and a TV monitor. The unit is controlled by a micro processor on the basis of data relating to latitude, longitude and heading of the aircraft.
U.S. Pat. No. 4,689,748 discloses a device for use on aircraft or spacecraft providing data corresponding to the course and orientation of the craft, and a digital display of the terrain over which the craft is travelling. It is a digital image scanning device, making use of the principle of aerial triangulation by tying in sequential images. The device, in combination with a computer, produces information in digital form and with unequivocal co-ordinate determination. F.i. distortion-free representation or read-out of the terrain can be produced.
U.S. Pat. No. 4,543,603 discloses a reconnaissance system comprising an air-borne vehicle capable of moving above a territory to be surveyed by rotating about its longitudinal axis, and means for taking images disposed on board the vehicle to observe said territory by a helicoidal scanning in relation with the rotation of the vehicle, wherein the vehicle is of the self-propelled missile type and the sensitive members are formed by at least one linear assembly of photosensitive elements disposed parallel to the longitudinal axis of the missile to give at each line an image of an elementary strip of territory which scans a strip of territory upon each revolution of the missile, the total image of the territory being formed by the plurality of images of the successive strips.
DE Pat. No. 3,235,993 discloses a system for electronic recording of commercial available maps on audio tape for instance in order to use these tapes in cars or other places, by reproducing (parts of) these maps on a monitor.